add plugin for fetching metrics from devices supporting the IF-MIB RFC 1537
Updated check-http and check-procs with help

I also added a couple :longs in there too, I added them to
chef-monitor by @portertech, he asked me to push the changes here too.
fix rubocop complaints
updated per @kalabiyau suggestions
reinstated :request_uri
reference correct rfc
enable SNMP version as a command line option for check-snmp.rb
enable SNMP version as a command line option for snmp-metrics.rb
Merge pull request #418 from DoubleNegativeVisualEffects/snmp_version

enable setting the SNMP version as a command line option for check-snmp.rb and snmp-metrics.rb
Merge pull request #412 from jjasghar/check_httpandproc_help

Updated check-http and check-procs with help
Merge pull request #398 from joemiller/snmp-if-metrics

add plugin for fetching metrics from devices supporting the IF-MIB RFC 1537